2018 Hurricane Briefing for the Institute for Catastrophic Loss Reduction Bob Robichaud Warning Preparedness Meteorologist Canadian Hurricane Centre Contents • Tropical Cyclones 101 • Review of the 2017 Hurricane Season • Outlook for the 2018 Hurricane Season • Sources of information for monitoring hurricanes Tropical Cyclones 101 Tropical Cyclones • Tropical cyclone is the generic term for such storms as hurricanes, tropical storms, typhoons, etc…. • They form over the warm tropical waters around the world • Tropical cyclones serve the purpose of redistributing energy stored in the ocean into the atmosphere All hurricane tracks:1842-2017 Hurricane Climatology Hurricane Origin and Track by Month June July August September October November Checklist for tropical cyclone formation • Warm ocean waters that is sufficiently deep • Unstable atmosphere • High humidity in the lower levels of the atmosphere • A minimum distance of at least 500 km from the equator • A pre-existing near- surface disturbance • Low wind shear Tropical Cyclone – Nature’s Heat Engine Tropical Cyclone Classification Hurricane Major Hurricane Tropical Storm Category 1 Category 2 Category 3 Category 4 Category 5 Wind > 63 km/h 119-153 km/h 154-177 km/h 178-208 km/h 209-251 km/h Wind > 252 km/h Debby Hermine Juan Joaquin Floyd Irma (2012) (2016) (2003) (2015) (1999) (2017 Allison Isaac Arthur Gaston Harvey Patricia (2001) (2012) (2014) (2016) (2017) (2015) Minimal Damage Some Damage Extensive Devastating Catastrophic Catastrophic Damage Damage Damage Damage Tropical vs. Non-Tropical Storms Tropical Cyclone Non-Tropical Cyclone • Fueled by the warm water • Fueled by the horizontal contrast in air temperature • Slow-moving • Generally faster-moving • Symmetrical • Asymmetric Major Hurricane Irma 2017 Winter Storm January 2018 From Tropical to Post-Tropical Wind Storm becomes post-tropical, Heavy rain moving very fast, heavy rain Strongest winds on the left, strongest winds on the right Storm size increases, rain begins to shift left of track Strengthens to a hurricane, moves slowly westward Storm forms Storm starts to speed off Africa up and curve northward Tropical Cyclone Hazards Hurricane Season 2017 in Review 2017 Hurricane Season 2017 Hurricane Season Storm Tracks 2017 Hurricane Season Storm Tracks Early start to hurricane season • First storm of the season was TS Arlene which formed on April 19th • TS Bret and Cindy formed in June – no impact from Bret but Cindy resulted in 2 fatalities • TS Don and Emily formed in July – no impact from Don but Emily resulted in flooding in southern part of Florida • In early August, Franklin became the first hurricane of 2017 although was short- lived and impacts were minimal • Hurricane Gert formed in mid August but stayed offshore (Cat 2) Hurricane Harvey • Harvey started as a typical weak August tropical storm that affected the Lesser Antilles • After some weakening Harvey began to re-intensify after crossing the Yucatan • Harvey rapidly intensified into a category 4 August 25th making landfall along the middle Texas coast • Persistent heavy rains caused catastrophic flooding, and Harvey is the second-most costly hurricane in U.S. history, after accounting for inflation, behind only Katrina (2005) Hurricane Harvey • Landfall along the Texas Gulf Coast late on August 25th as a Cat 4 • First Major Hurricane to make landfall in the U.S. since 2005 • Peak recorded wind speed of 229 km/h • 57 reported tornadoes with Harvey • Significant storm surge was also reported (as high as 2- 3 m) Hurricane Harvey • Very slow movement of the storm over the next few days resulted in extreme rainfall • Harvey was the most significant tropical cyclone rainfall event in United States history • The highest storm total rainfall report from Harvey was 1539 mm • Radar estimates indicated that the peak rainfall could be in the 1600 to 1800 mm range • The rainfall was also extreme in areal coverage Hurricane Harvey Hurricane Harvey Rainfall Comparisons millimetres Hurricane Harvey - Impacts • At least 68 people died from the direct effects of the storm in Texas • Over 300,00 structures were flooded • Up to 500,000 cars were flooded • 40,000 people evacuated or took refuge • About 30,000 water rescues were reported • 336,000 customers lost power • Oil refineries were shut down for extended periods Hurricane Harvey - Impacts • About 75% of the flood damage occurred OUTSIDE the 100-year flood zone • 80% of flood victims DID NOT have flood insurance • Preliminary estimates for damage costs are at $125 B U.S. • Recovery continues Hurricane Irma • Developed off the coast of Africa in late August and became a hurricane early on August 31st • Eventually reached Cat 5 with winds of 290 km/h • Landfall in Barbuda and St Martin at peak intensity • Two more landfalls as Cat 5 – British Virgin Islands, Cuba and one as Cat 4 in Bahamas Hurricane Irma • Irma made its 6th landfall in the Lower Florida Keys on September 10th as a Cat 4 Hurricane • Final landfall was near Marco Island before the storm crossed the spine of Florida • Peak wind was 257 km/h (unofficial report of 320 km/h) • Peak wind in the U.S. was 193 km/h in the Florida Keys • 21 tornadoes were reported Hurricane Irma • Positive storm surge was reported at several location in the Caribbean and in the U.S. • Offshore winds on the northern side of Irma’s circulation initially caused a negative storm surge and receding water levels along Florida’s West Coast • Some normally submerged areas went virtually dry, allowing people to walk out onto the sea or bay floor • This is a very dangerous situation as the water will eventually rise and rise rapidly Hurricane Irma - Impacts • 129 fatalities, 44 direct and 85 indirect • About $50 B U.S. in damages • Widespread devastation in the Caribbean • Total destruction on the island of Barbuda • Entire island was left the island – totally uninhabited for the first time in 300 years • 150,000 homes damaged in Cuba • Lower Florida Keys were devastated Hurricane Irma - Impacts • Largest evacuation in U.S. history (6.8 Million) • Significant flooding along the east coast of Florida • Combination of storm surge and heavy rain resulted in worst flooding in Jacksonville in over 225 years • Wind impacts extended into Georgia and the Carolinas • Extreme focus on the track resulted in some misinterpretation of the forecast for Florida Hurricane Season 2017 Continues • Jose formed in early September and intensified rapidly to Cat 4 then meandered off the coast of New England for a few days • Katia was a short-live Cat 2 hurricane that formed in the Gulf of Mexico • Lee formed in mid- September and reached Cat 3 but stayed offshore Katia Irma Jose Hurricane Maria • Maria also formed over the central Atlantic in mid- September • Rapidly intensified to a major hurricane eventually reaching Cat 5 with winds 282 km/h • Ravaged the island of Dominica with winds of 269 km/h • Direct hit on Puerto Rico with winds of 250 km/h • Approached Carolina coast before making a hard right turn Hurricane Maria - Impacts • 112 fatalities direct fatalities, likely well over 1,000 indirect fatalities so far • Dominica sustained catastrophic damage • $90 billion USD in damage (3rd costliest hurricane in U.S. history) • Electric grid was devastated (80% of utility poles were destroyed) • Practically all cell phone service was lost and municipal water supplies were knocked out • Recovery still very much ongoing today Hurricane Nate • Nate was a Cat 1 Hurricane that formed in early October and impacted Central America and the U.S. Gulf Coast • Close to 500 mm of rain reported in Central America • 44 fatalities • Flooding and mudslides in Costa Rica • Heavy rain, flooding and storm surge were reported in the U.S. • About $800 million in damage Hurricane Season 2017 Continues • Ophelia was a storm that formed in mid-October and became the final hurricane of 2017 • Ophelia reached Cat 3 and followed an odd track that brought it into Europe as a strong Post-Tropical Storm • Phillip was a late October TS – minimal impacts • Finally Rina formed in early November. With Rina, 2017 became the only season with a named storm in every month 2017 Hurricane Season Summary • 2017 was an historic season with several new records set during the season – 7th most active year in the last 167 years • 6 major hurricanes formed in 2017, the most since the hyperactive 2005 season • Costliest year for hurricanes – $265 Billion • 2nd (Harvey), 3rd (Irma) and 5th (Maria) costliest U.S hurricanes • Five Category 5 landfalls • Three Category 4 landfalls in the U.S in 26 days – only three in the previous 56 years!! • First time the U.S. had two landfalling category 4 hurricanes the same year – Harvey and Irma • Harvey set a new record for tropical cyclone-generated rainfall in the U.S. with 1539 mm 2017 Hurricane Season Summary • 37 cases of rapid intensification (strengthening of the wind speed by at least 55 km/h in 24 hours) in 2017 – only 6 were correctly forecast by NHC • Ophelia was the farthest east that an Atlantic major hurricane had ever been observed Factors Influencing Hurricane Season Water Wind Shear Multi-decadal Temperature cycle Less More active Less active Average Current Water Temperature Current Water Temperature Latest Atlantic Sea Surface Temperature Pattern Water temperatures are warmer than normal Water temperatures are cooler than normal Factors Influencing Hurricane Season Water Wind Shear Multi-decadal Temperature cycle Less More active Less active Average Factors Affecting Hurricane Season May